Architectural coatings or decorative coatings include house paints for both interior and exterior applications. Such paints have been used over the years for protective and decorative purposes. The paints are used to protect the substrate on which the paint is applied from light, heat and corrosion. The functional purpose of the paint includes its ability to fill and protect the irregularities of the surface it protects. Most paints are made up of four basic groups of raw materials: 1) binders or resins; 2) tinters (pigments and/or colorants); 3) solvents; and 4) additives. When a paint is applied to a surface, the solvents evaporate while the binder, pigments and additives remain on the surface to form a protective dry solid film.
Up until the 1940's, paints were almost all solvent based. Now in the early 21st century, more than 70% of the architectural coatings market is water-based paints due to its comparable performance and the environmental regulations in the United States. Universal colorants are desired because they are compatible in both solvent-based alkyd as well as water-based acrylic latex emulsions. Colorants are used in architectural coatings not only for appearance, but also for further performance parameters including gloss, weatherability, and hiding properties. Many of these parameters have been improved by use of colorants containing volatile organic compounds (VOCs).
Focus on VOCs of the paints by the consumers and the various regulatory agencies at both the federal and the state level has resulted in the awareness of the benefits of low VOC colorants in the tinters of the paints. In addition to VOCs, regulatory agencies, such as the EPA, regulate hazardous air pollutants (HAPS), which include alkylphenol ethoxylate surfactants (APE). APE has been used in paints as a wetting agent and also for pigment dispersion and temporarily stabilizing the pigment dispersion from re-aggregating and re-agglomerating.
Universal colorant compositions are described for example in WO-A 2006/102 011. Pigment dispersions in universal applications are described in U.S. Pat. Nos. 5,934,513, 5,897,698, 5,340,394 and 6,287,377.
Despite the fact that the universal colorant compositions have been known for some time, and some even attempting to have low VOC levels, there is still a great need for ultra low VOC universal colorant compositions with exceptional coating applications which match or exceed the performance of current regular VOC universal colorants.